Published in The Hindu on December 13, 2012

A large-scale study undertaken recently in Tamil Nadu has confirmed the high prevalence of hypertension.

The study published in the International Journal of Public Health reported 21.4 per cent prevalence in about 10,500 people studied (aged 25-64) in 11 villages. Prevalence was nearly the same in both sexes.

Though earlier studies documented 16 per cent prevalence in rural areas, studies carried out later put it 20 per cent. In urban areas prevalence is 22-30 per cent. A large percentage of people were found to be ignorant of their condition. “About 75 per cent of people with hypertension were ignorant of their condition,” said Dr. Prabhdeep Kaur, the first author of the study and a Scientist at the National Institute of Epidemiology, Chennai. “It [ignorance] was more in the younger age group.”

The proportion of people (both males and females) whose hypertensive status was newly diagnosed decreased with age and awareness of the condition.

Hypertension is one of the major risk factors for heart attack, stroke and kidney failure. According to the paper, about 24.5 per cent of deaths in people aged 45-59 years in rural Tamil Nadu are caused by diseases of the circulatory system.

The percentage of people who were on treatment was just 20 per cent. Of this, a mere 6.6 per cent had their blood pressure under control.

People were classified as suffering from hypertension if their systolic blood pressure was above 140 mmHg or diastolic blood pressure was above 90 mmHg or when both systolic and diastolic blood pressures were above normal.

A significant population had only systolic (nearly 29 per cent) or diastolic (31 per cent) blood pressure above normal. “Older people tend to have isolated systolic hypertension, and isolated diastolic hypertension is more prevalent in younger people,” Dr. Kaur said.

Central obesity (a big paunch) and body mass index (BMI) of more than 23 were found to be positively related to hypertension. “Alcohol emerged as an important risk factor among males,” the paper notes.

High prevalence, low awareness, low treatment rates, and poor control in those under treatment in the rural areas make hypertension an “emerging public health challenge.”